Polymeric coating for the protection of objects

Abstract

A protective polymeric coating is applied to the surface of various objects which are to be exposed to a harsh environment. The protective polymeric coating covers the exposed surface, where the polymeric coating includes a polyimide polymer. The polyimide polymer in the polymeric coating has a backbone with at least one non-terminal phenyl group. A linkage is connected to the non-terminal phenyl group, where the linkage can be an amide linkage or an ester linkage. An oligomeric silsesquioxane compound is connected to the linkage through an organic substituent, where the oligomeric silsesquioxane is not incorporated into the polymer backbone. The polymeric coating provides protection to the underlying object.

1. A method of protecting an object comprising:
 (a) reacting at least one acid monomer with at least one diamine monomer to form a polyamic acid backbone, where the monomers are selected such that the polyamic acid backbone includes a non-terminal attachment point; 
 (b) after step (a), imidizing the polyamic acid backbone to form a polyimide polymer backbone; 
 (c) after step (b), attaching an oligomeric silsesquioxane (OS) compound to the attachment point on the polyimide polymer backbone, such that the OS compound is connected to the polyimide polymer backbone; 
 (d) providing an object with a surface; 
 (e) protecting the surface from atomic oxygen and ultraviolet light with a polymeric coating, where the polymeric coating includes the polyimide polymer backbone. 
 
     
     
       2. The method of  claim 1  where a polymer backbone is isolated a maximum of one time, where the polymer backbone includes the polyamic acid backbone and the polyimide polymer backbone. 
     
     
       3. The method of  claim 1  further comprising positioning the object in the presence of atomic oxygen. 
     
     
       4. The method of  claim 1  where the monomers are selected such that the polymeric coating is soluble. 
     
     
       5. The method of  claim 1  where the entire surface is covered by the polymeric coating. 
     
     
       6. The method of  claim 1  where the OS is in the form of a polyhedron. 
     
     
       7. The method of  claim 1  where a functional group is connected to the OS and the functional group is reacted with the attachment point to attach the OS to the polyimide polymer backbone, where the attachment point is comprised of a carboxylic acid and where the functional group is selected from the group consisting of an amine and an alcohol. 
     
     
       8. The method of  claim 1  further comprising placing the object in a high altitude environment. 
     
     
       9. The method of  claim 1  where the polymeric coating produces a layer of silicon dioxide when exposed to atomic oxygen. 
     
     
       10. The method of  claim 1  further comprising curing the polymeric coating on the object at a temperature not exceeding 100 degrees centigrade. 
     
     
       11. The method of  claim 1  further comprising curing the polymeric coating on the surface of the object at a temperature not exceeding 150 degrees centigrade. 
     
     
       12. An object comprising:
 a surface of the object; 
 a polymeric coating covering the surface, where the polymeric coating comprises a polyimide polymer, where the polyimide polymer has a 50% transmittance wavelength shorter than the wavelengths of the visible spectrum such that a film of the polyimide polymer is colorless, the polymeric coating comprising:
 a polyimide polymer backbone, where the polymer backbone includes at least one non-terminal phenyl group; 
 a linkage selected from the group consisting of:
 an amide linkage comprising a carbonyl carbon and a linking nitrogen atom, wherein the carbonyl carbon is connected by a single bond to the non-terminal phenyl group in the polymer backbone and the linking nitrogen atom is connected by a single bond to the carbonyl carbon; 
 an ester linkage comprising a carbonyl carbon and a linking oxygen atom, wherein the carbonyl carbon is connected by a single bond to the non-terminal phenyl group in the polymer backbone and the linking oxygen atom is connected by a single bond to the carbonyl carbon; and 
 a combination of the amide linkage and the ester linkage; 
 
 at least one oligomeric silsesquioxane (OS) compound comprising silicon atoms and oxygen atoms connected together, and 
 an organic substituent connected to each silicon atom of the OS compound, wherein at least one organic substituent is connected to the linkage. 
 
 
     
     
       13. The object of  claim 12  where the object is a component of a space craft. 
     
     
       14. The object of  claim 12  where the object includes a carbon-based component. 
     
     
       15. The object of  claim 12  where the OS is in the form of a polyhedron. 
     
     
       16. The object of  claim 12  where the polymeric coating protects the object from ultraviolet light. 
     
     
       17. The object of  claim 12  where the polymeric coating has a thickness of 1.5 mils or less, and the polymeric coating is colorless such that the human eye does not detect color in the polymeric coating. 
     
     
       18. An object resistant to atomic oxygen attack comprising:
 an object including a surface; 
 a polymeric coating positioned over the surface, where the polymeric coating comprises a polyimide polymer having a 50% transmittance wavelength shorter than the visible spectrum such that the a film of the polyimide polymer is colorless, the polyimide polymer having a polyimide polymer backbone including at least one unit represented by the following formula: 
 
       
         
           
           
               
               
           
         
         wherein X includes an oligomeric silsesquioxane (OS) compound, and XX is an oxygen atom; wherein YY is selected from the group consisting of the compounds represented by the following formulas: 
       
       
         
           
           
               
               
           
         
         and wherein ZZ is selected from the group consisting of a direct bond, —O—, —S—, —SO—, —SO 2 —, —CH 2 —, —CF 2 —, —C(CH 3 ) 2 —, —(CF 3 ) 2 —, —(CH 2 ) n —, —(CH 2 CHCH 3 O) n —, —((CH 2 ) 4 O) n —, —(Si(CH 3 ) 2 O) n —, —SiH(CH 3 )O) n —, —SiH(C 6 H 5 )O) n —, and —Si(C 6 H 5 ) 2 O) n —, and wherein WW is selected from the group consisting of hydrogen and a compound represented by one of the following formulas: 
       
       
         
           
           
               
               
           
         
       
     
     
       19. The object of  claim 18 , wherein the polymer includes at least one unit represented by the following formula: 
       
         
           
           
               
               
           
         
       
     
     
       20. The object of  claim 18  where the polymeric coating has a thickness of 1.5 mils or less, and the polymeric coating is colorless such that the human eye does not detect color in the polymeric coating.